Fields of Spiral Conformal Arrays Using Huggins Scanning and a Conformal Feed Network for a Circular Array.

An array of fan-shaped segments arranged in a spiral-like manner is described. The fan-shaped segment, which may consist of a board of stripline or microstrip, contains several radiating elements phased by the Huggins or I.F. method. The fields produced by single segments are calculated and the characteristics of the radiated beams are given. Quantitative expressions for the field produced by spiral arrays are derived and examples of field patterns and beam properties are given. A method is presented for coupling the outputs of an array of segments to feed a circular array to obtain conformal scanning. When used in this latter manner, the dimensions of an array of segments can be greatly reduced.